Plastic chair



FIG. 1 is a front right isometric view of a plastic chair showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a back view. 

The ornamental design for a plastic chair, as shown. 